The mean number of children that would be born alive to a woman during her lifetime if: (1) she were to experience the exact current age-specific fertility rates; and (2) she were to survive from birth through the end of her reproductive life. The total fertility rate is obtained by summing the single-year age-specific rates at a given time.

The mean number of children that would be born alive to a woman during her lifetime if she were to survive and pass through her childbearing years conforming to the fertility rates by age of a given year.